The present invention relates to a device for holding dental floss for the purpose of facilitating the removal with same of foreign matter lodged between adjacent teeth in the mouth. The invention is more particularly concerned with a dental floss holder of the type wherein a length of dental floss can be held under tension.
Various dental floss holders have already been described, for instance, in U.S. Pat. Nos. 1,815,408 and 2,354,454. The dental floss holder of U.S. Pat. No. 1,815,408 is adapted to hold under tension a special type of dental floss having knots or enlargements at predetermined lengths therealong and, to this end, it comprises a pair of opposed spaced-apart floss anchoring arms which are slitted at their terminal ends to receive the floss, each slit intersecting a recess formed in the outer side of each arm and having a size and shape to accommodate a knot of the floss. Since the arms are resilient and the length of floss between two successive knots is slightly smaller than the distance between the terminal ends of the arms, by first compressing the arms so as to yield towards each other and inserting the length of floss between two successive knots through the slits at the terminal ends of the arms and then releasing the arms, the knots will engage the recesses in the arms and remain anchored therein, thus resulting in the tensioning of the length of floss therebetween. This dental floss holder, however, has a drawback in that the floss often gets dripped between the walls of the slits and thereby prevents the arms from springing back toward their initial positions, and it is thus often necessary to pull the arms away from each other so as to ensure that the knots are securely seated in the recesses formed therein. Also, since dental floss is generally a multi-filament thread, some filaments do get split apart when the floss is inserted in the slits owing to the right frictional engagement with the walls of the slits, causing the floss to fray.
The dental floss holder proposed in U.S. Pat. No. 2,354,454, on the other hand, is adapted to hold under tension a conventional floss, that is, one having a substantially uniform cross-section throughout its entire length. The holder similarly has a pair of opposed spaced-apart resilient arms but these are provided with aligned floss receiving notches at their terminal ends, instead of slits. Outwardly extending cleats are arranged on the outer sides of the arms remote from the terminal ends thereof for the purpose of anchoring the end portions of a length of such a floss which has been inserted in the notches at the terminal ends of the arms. Laterally projecting lugs are also provided on the outer sides of the arms between their terminal ends and the cleats thereon. Since the portions of floss between the cleats and the terminal ends of the arms extend in straight lines along the outer side edges of the arms once the floss has been engaged with the notches and the cleats, by snapping these portions of floss across the lugs the floss will be stretched and placed under tension. Thus, tensioning of the floss is achieved only after it has been engaged with the notches and the cleats and the arrangement does not enable one to adjust the tension to different values. A further drawback resides in that the floss has a tendency to get wedged in the notches and thereby to prevent the arms from inwardly yielding towards each other during movement of the floss into engagement with the lugs, which as a consequence hinders the tensioning of the floss.